Understanding and Controlling Variations in DCB Test Results

Two test labs working for a seamless pipe manufacturer launched a test program to better evaluate the DCB test variability and to understand the factors of variation. The objective was to be able to give the same KISSC values independently of the testing lab. Testing labs A and B evaluated their initial differences through inter-laboratory testing, selected the factors of variations and used an original Taguchi design of experiment approach that allowed the investigation of a quite large number of factors within a limited number of tests. Among the selected factors, variations of the arm displacement within the NACE TM0177 limits explained nearly 70% of the observed variance.